The antibiotic your doctor started for your cough and cold is one that's commonly used and considered safe in pregnancy, and it's reassuring that whoever prescribed it knew you're 16 weeks along. Finishing the full course exactly as your doctor set it is what protects you and your baby best, since stopping early can let the infection come back or not clear properly.
Next Steps
Continue the course as prescribed, drink plenty of warm fluids, and try steam inhalation for the congestion. If the cough hasn't settled by the time the course ends, check back with your doctor.
Health Tips
Please see your obstetrician the same day if you develop fever, breathlessness, or feel unusually unwell, since these need prompt review in pregnancy.